I enjoyed immensely Bart and Cindy in Lifetime’s Seeds of Yesterday, the 4th and final installment in their Flowers in the Attic/Dollanganger movie series, adapted from the book series by V.C. Andrews.
I had not read beyond the first book, but the movie adaptations did such a good job of making the series appeal to me more than it ever had before that I’ve recently read them all.
Lamentably, Bart and Cindy are not canon in the book the way they are in the movie adaptation (four for you, Lifetime), but it’s still a very suggestive relationship and I kept track of quotes about their relationship as I was reading along.
(Of course I immensely enjoyed Cathy and Chris as well, but that’s for another time.)
If you’re interested in more Bart/Cindy, here is my tag for them on my tumblr.